Control device having improved testing properties

ABSTRACT

The invention relates to a drive electronics for driving a display with a matrix  101  of picture elements. The drive circuit  102   x  and  102   y  for generating signals for driving the pixels via control lines  103  is provided with signals at the input terminals  110  via contact areas  104 . In addition to the contact areas used for the generation of arbitrary pictures, there exist contact areas  105  used within the framework of a testing method. These contact areas for the testing method are also connected with the input terminals  110  of the drive circuit and are used for generating a test pattern.

The present invention relates to the testing of an optoelectronic deviceand to an optoelectronic device modified for testing. Thereby, theoptoelectronic device has the form of a display device with pixels.Particularly, the present invention relates to a drive electronics fordriving an optoelectronic device, an arrangement of test contact areasand a method for testing an optoelectronic device, especially having theform of a display with pixels.

Together with the increasing demand for display elements without acathode ray tube, the requirements for liquid crystal displays (LCD andother display elements using switching elements like, e.g., thin filmtransistors (TFT) increase. In these display elements the so-calledpixels are arranged in a matrix.

In general, the switching elements of each pixel are driven via controllines, i.e. gate lines, and data lines. In order to avoid charging ofthe pixel elements, the control lines can be shorted via shorting barsduring manufacturing. Otherwise, charging of the pixel elements mayresult in destruction of the switching elements or the correspondingpixels.

Moreover, developments are underway to—in addition to the pixelelements—apply peripheral drive circuits directly to the glas substrate.Thus, the external driving of the display elements is simplified. Such adisplay apparatus with integrated drive circuits is described indocument DE 198 32 297. In this event, the number of contact areasrequired for the picture control can be reduced. Without such drivecircuits, each control line must have a contactable are to allow forpicture control during operation. The areas contactable by an externalcontrol are also called pads.

To assure high picture quality, only very few of, e.g., several millionsof pixels can be accepted to be defective. To provide low costproduction, it is very important, especially for the ever larger displayelements, to provide efficient online-testing methods. Such a testingmethod is disclosed, e.g., in EP 0 523 584. In this testing method,individual pixels are tested by a particle beam. The particle beam canbe used to either detect the charge applied via the lines and/or applycharge to a pixel electrode.

Document U.S. Pat. No. 5,081,687 (Henley et al.) describes a method andapparatus for testing LCD displays. Therein, each second data line andeach second gate line is connected with a shorting bar. A test pictureis generated by driving the shorting bar. During testing, a voltage of,e.g., −5 V is applied to the electrodes of each second pixel and avoltage of, e.g., +5V is applied to the electrodes of the intermediatepixels to form a test picture. Such shorting bars cannot be providedtogether with integrated drive circuits without troubles because theywill short-circuit the driver outputs.

Document U.S. Pat. No. 5,936,687 (Lee et al.) utilizing a drive circuituses contact pads for generating a test picture, said contact pads beingconnected with a circuit in order to avoid electrostatic discharge(ESD). This circuit comprises shorting bars which are connected viadiodes to the lines for driving the individual pixel elements. Indocument U.S. Pat. No. 6,337,772 (Ha et al.) transistors are used forconnecting the shorting circuits with the control lines.

The following conditions have to be fulfilled if test pictures aregenerated via the shorting bars connected with a drive circuit. Eitherthe drive circuits are not integrated at the time of the testing or theoutput terminals of the integrated circuits are formed such that they donot interfere with the test signals. In the majority of cases, thiscondition cannot be realized.

Furthermore, the following has to be considered. Shorting bars cannotalways be realized due to reasons of process, space or circuitry. Also,the function of the drive circuits is not testet with such a solution.Moreover, only simple test patterns can be generated, wherein theperiodically repeated unit cell of said test pattern cannot be largerthan the number of shorting bars.

If using, for generating a test picture, the pads used during normaloperation, especially for large display elements a plurality of contactareas must be contacted during testing. This is especially difficultwhen large display elements are tested since the display element must beshifted during the testing method. For smaller displays, a pluralitythereof is arranged on the glas so that also in this case the glassplate must be repeatedly shifted during the testing procedure. Thus,increased requirements are demanded for the contacting block. Thecontacting block serves external signal input to the contact areas ofthe drive circuit or to the contact areas of the data lines or gatelines or the corresponding shorting bars.

The above mentioned problems of the prior art are solved by inventiveapparatus according to claims 1, 14, 21 and 29 as well as the inventivemethod according to claims 22 and 28.

According to an aspect of the invention, the object is solved by a driveelectronics for driving an optoelectronic device with a matrix ofpicture elements. The drive electronics has a drive circuit with inputterminals and output terminals. Further to this, the drive electronicsincludes a first arrangement of contact areas connected with the drivecircuit and a second arrangement of contact areas connected with thedrive circuit. Preferably, both arrangements of contact areas areconnected with the input terminals of the drive circuit.

Furthermore, the first arrangement of contact areas has first contactareas and the second arrangement of contact areas has second contactareas. Preferably, the second contact areas of the second arrangement ofcontact areas are larger than the first contact areas of the firstarrangement of contact areas.

The present invention allows to generate a test pattern which issufficiently complex for the purpose of testing via the secondarrangement of contact areas. For testing purposes, no arbitrarypictures have to be generated but patterns which are less complexcompared to normal operation. Therefore, the number of contact areas forgenerating a test pattern can be reduced compared to the number ofcontact areas for generating an arbitrary picture during normaloperation. This reduction of the number contact areas allows that thecontact areas can be enlarged. Thus, it is possible to test displayelements in a reliable, quicker and more effective fashion.

The drive electronics is preferably designed so that the number of inputterminals of the drive circuit, by which the arrangement of contactareas for testing the drive circuit is connected, is at maximum 5%,preferably at maximum 1%, and especially preferred at maximum 0.5%, thenumber of output terminals of the drive circuit, by which the controllines to the picture elements of the display matrix are connected withthe drive circuit.

According to another aspect of the invention, the object of theinvention is solved by an arrangement of test contact areas forproviding an optoelectronic device with signals for generating a testpattern. The optoelectronic device comprises a matrix of pictureelements. This arrangement has at least one pad, i.e. at least onejunction area, and at least on connectioin of the at least one pad to adrive circuit, wherein the drive circuit is provided with signals via anarrangement of operating contact areas during normal operation.

According to a further aspect of the present invention, the object issolved by an optoelectronic device with a matrix of picture elements, atleast one drive circuit, a first arrangement of contact areas connectedwith the drive circuit and a second arrangement of contaqct areasconnected with the drive circuit.

A further aspect for solving the object underlying the invention is amethod for testing an optoelectronic device with the steps of: providinga contact between an external control and an arrangement of contactareas, providing input signals to an input terminal of the drive circuitvia the arrangement of contact areas to generate a test pattern on amatrix of picture elements, and testing the picture elements of thematrix of picture elements.

A further aspect for solving the object underlying the present inventionrelates to a method for manufacturing a drive electronics of anoptoelectronic device with a matrix of picture elements. Therein, thefollowing steps are accomplished: a drive circuit is provided on asubstrate, control lines of the matrix of picture elements are connectedwith output terminals of the drive circuit, a first arrangement ofcontact areas is provided on the substrate, the first arrangement ofcontact areas is connected with input terminals of the drive circuit, asecond arrangement of contact areas is provided on the substrate, andthe second arrangement of contact areas is connected with inputterminals of the drive circuit.

Preferred embodiments and specific aspects of the invention are apparentfrom the dependent claims.

Embodiments of the invention are illustrated in the drawings and will beexemplarily explained in the following.

FIG. 1 a shows a schematic view of an embodiment of the presentinvention.

FIG. 1 b shows a cutout of the embodiment of the present invention shownin FIG. 1 a.

FIG. 1 c shows an alternative of the section shown in FIG. 1 b.

FIG. 2 shows a schematic view of a second embodiment of the presentinvention.

FIG. 3 a shows a schematic view of a further embodiment of the presentinvention.

FIG. 3 b shows a cutout of the embodiment of the present invention shownin FIG. 3 a.

FIG. 4 shows a diagram of a pixel representation of a test pattern, and

FIG. 5 shows a schematic view of a display element according to theprior art.

FIG. 5 is an embodiment according to the prior art. Therein, a schematicoverview of a display element 10 is shown. The individual pixels 30 areconnected with the drive circuits 12 via control lines 13 for drivingthe pixels. During normal operation, the drive circuits are externallyprovided with signals via contact areas 14. In FIG. 4, only five contactareas 14 are symbolically illustrated. However, several hundereds ofthese contact areas may be required for large display elements toprovide the dive circuits with signals.

The control lines 13 are connected with a shorting circuit via switchingelements 22. This shorting circuit against electrostatic discharge (ESD)provides protection either only against overvoltages and allows forapplying normal operational voltages or can be switched off by means ofthe contact areas 20 during testing and during normal operation. Theshorting circuits for the data lines and the gate lines are coupled toeach other via the coupling circuits 24. All the above-describedelements are integrated on the glas substrate.

This conventional embodiment has the following drawbacks. A test patternfor an online-testing method is generated via the contact areas 14 ofthe drive circuits. Sinc these contact areas are very small due to theirnumber, contacting during the test procedure is difficult. This isespecially true for large display elements which are so large that amechanical shift must be accomplished during the test procedure. Such ashift may be necessary if, e.g., the deflection of a particle beam isnot sufficient for testing the whole display. For a large number ofcontact areas with a size of, e.g., below 80 μm, highly advancedcontacting technology must be employed to avoid erroneous testing due toerroneous contacting. The technical requirements increase even more ifthe size of the display requires shifting during testing.

For cost-effective testing, high speed must further be realized.Furthermore, additional requirements for the contacting mechanics aremade by testing method. Taking this into consideration, it becomesapparent that the requirements cannot be fulfilled by the present priorart. Further requirements for the contacting mechanics for, e.g., thetesting with a particle beam are: use in an vacuum environment, lowmagnetic field generation to not interfere with an electron beam or ameasurement signal, and free access to the area of the pixel matrix forthe particle beam.

Preferred aspects and embodiments of the present invention are nowdescribed with reference to FIGS. 1 to 4.

FIG. 1 a shows a display element 100, like e.g. a display for a cellphone, a PC or a TV set. The pixels of the pixelmatrix 101 are arrangedmatrix-like. For picture generation, the pixels are driven via controllines 103 x and 103 y, respectively. Additionally, drive circuits 102 xand 102 y are provided on the substrate to facilitate the externaldriving for picture generation. Like pixel matrix 101, also the drivecircuits are applied to the substrate during the manufacturing. Thedrive circuits are provided with signals by an external drive via pads104 b. Thereby, the signals are transmitted to the drive circuits vialines 104 a. Pads 104 b and lines 104 a together form the contactableareas. They will be referred to also as contact areas in the following.

In practice, especially for large displays with many pixels up to morethan hundered of these contact areas (104 a and 104 b) exist. Therefore,these contact areas cannot be designed sufficiently large due to therestricted available space to guarantee efficient and reliable testing.Taking for example a display with a size of 4 inches (640×480 pixels),these contact areas according to the prior art have a size of about 60μm times 2000 μm. During testing of the display element and theindividual pixels of the pixel matrix, resp., with, e.g., an electronbeam the following criteria have to be fulfilled. Firstly, a testpattern must be generated via an external drive. The contacting of thepads 104 b must be accomplished certainly and reliably. Due to the sizeof the display element, it may be necessary to move the display withrespect to the electron beam. In order to provide high speed testing,the contacting must be continously carried along or it must be detachedand reattached as quick and reliable as possible. Furthermore, thecontacting block providing the contacting must fuction under vacuumconditions and must not interfere with an electron beam and theelectrons to be detected, resp., because testing with an electron beamis not longer possible.

An error-free and efficient contacting is difficult or even impossibleunder these boundary conditions. Therefore, additional contact areas fortesting are provided according to the invention. They consist of thepads 105 b and the lines 105 a connected thereto. Since no arbitrarypictures but only sufficiently comples patterns have to be generated onthe display for testing, the number of these test contact areas can bereduced compared to the number of contact areas used during normaloperation. Compared to the number of operational contact areas, thenumber of test contact areas (105 a and 105 b) can be reduced to amaximum of 90%, preferably a maximum 50%, and more preferably a maximumof 20%. Thus, for, e.g., a large display about 30 contact areas for thetesting method are provided in addition to the about 200 contact areasfor normal operation whereas for a small display with about 30 contactareas for normal operation about 5 additional test contact areas areprovided.

From this it follows that the number of input terminals of the drivecircuit 102 x connecting the drive circuit to the second arrangement ofcontact areas 105 has a maximum of 5% of the number of output terminalsconnecting the drive circuit to the control lines 103 x of the matrix ofpixels 101. This means that, according to the prior art, the pads usedduring testing are connected with the output terminals of a possibledrive circuit via control lines. Typically, this drive circuit is ashorting bar attached to the control lines. In contrast to this, in thepresent invention the pads for generating a test picture are connectedwith the drive circuit via the input terminals of the drive circuit. Thenumber of connections between test contact areas and input terminals ofthe drive circuit is reduced compared to the number of output terminalsof the drive circuit connected with the control lines.

Therefore, it is possible to design the contact areas used for the testprocedure in a fashion so that the pads 105 b have a dimension of atleast 100 μm, preferably at least 0.5 mm, and especially preferred atleast 2 mm. The term dimension is to be understood as the expansion in adirection of the minimum value of expansion. Accordingly, the length ofthe shorter side of a rectangular pad must be considered the dimension.The above-mentioned dimension of the contact areas allows a reliable,quick and fault-immune contacting.

For generating a test pattern as it is described in more detail withreference to FIG. 4, the test pads 105 b are connected with the lines104 a according to a first embodiment via lines 105 a. The lines 104 aare used for pads 104 b of normal operation. Via these connections, oneor more test pads can be connected with the input terminals of of drivecircuits 102 x and/or 102 y. Furthermore, it is possible that a test padis connected with multiple lines 104 a for normal picture generation viaswitching elements or components (e.g. diodes, transistors or othercomponents). An example for such a connection is illustrated in FIG. 1 cwith a swichting element or component 120. Another option for connectingmultiple lines with a test pad is a connecting structure, which isremoved for normal operation. This means that the structure is cut off,e.g., during glas separation or by etch processes.

Accordingly, the present invention relates also to optoelectronicdevices, e.g. in the form of displays, adapted for a testing method withfirst and second arrangements of contact areas according to theinvention, the testing method being accomplished therewith and at leasta part of the test arrangement being cut off after the testing method.

Since no arbitrary patterns have to be generated on the display for atesting method, it is not mandatory that all input terminals 110 of thedrive circuit 102 x can be driven during the tests. However, it may beof advantage when at least all input terminals are held on a definedpotential to avoid floating of the input terminals. According to thepresent invention, test pads 105 b can be connected with operating pads104 b via lines 105 a of the test contact areas without departing fromthe gist of the present invention.

The terminals of a drive circuit 102 x according to an embodiment of thepresent invention are shown in FIG. 1 b. The control lines 103 x for thepixel matrix 101 (not shown in FIG. 1 b) are connected with the outputterminals of drive circuit 102 x. The lines 104 a and 105 a,respectively, are connected with the input terminals of the drivecircuit.

Therein, according to the present invention the term “output terminal”of the drive circuit should be understood in that the output terminalsare connected with the control lines used for controlling the individualpixels. An input terminal of the drive circuit should be considered as aterminal by which the drive circuit is provided with external signals.Thereby, these external signals are modified within the drive circuit tothen provide signals for the picture elements to the control lines 103 xcoupled to the output terminals.

FIG. 2 shows a schematic diagram of a further embodiment of a displayelement 100. Components similar or analogous to the embodiment shown inFIG. 1 a are desgnated by the same reference numerals and will not beexplained in detail in the following. In contrast to FIG. 1 a, the testcontact areas (105 a+105 b) of the present embodiment are connected withthe drive circuits 102 x and 102 y, respectively, via test drivecircuits 202 x and 202 y, respectively.

Therein, the test drive circuits 202 x and 202 y serve to convert thesignals received from the test contact areas (105 a and 105 b) intosignals for the drive circuits 102 x and 102 y. The drive circuits 102can process these converted signals for pattern generation and canprovide them to the pixels via the control lines 103.

Several realizations are possible for the test drive circuits 202. Onone hand an embodiment similar to FIG. 3 can be realized. Therein, thetest drive circuit provides input terminals for the test contact areasand transmits the signals to respective contacts of the drive circuits102.

On the other hand, also the following embodiment can be realized. Inthis embodiment, a memory is integrated into the test drive circuit 202.One or more test patterns are stored in that memory. The generation of atest pattern is started or stopped by external signals provided via testcontact areas 105. In the case of more than one stored test patterns,also one of the patterns is selected by the external signal. The testdrive circuit transmits the signals required for the test pattern to thedrive circuits 102. The test pattern is generated on the basis of thesesignals. According to this embodiment, it is possible to further reducethe number of contact areas or pads required for the testing method. Ifthe generation of the test pattern must only be started or stopped, thenumber of test contact areas can be reduced to the number of pads forvoltage supply and one control pad.

According to another embodiment, the test drive circuit 202 can alsoserve as a multiplexer. By multiplexing the signals, e.g., in the timedomain, it is possible to provide a plurality of signals via a smallnumber of test pads 105 b. In this embodiment, the buffer or possibletimer components required therefor are also integrated on the chip ofone of the drive circuits.

According to the embodiment shown in FIG. 3, the test contact areas 105are directly connected with the input terminals of the drive circuit ordrive circuits, respectively. For this purpose, either input terminalsfor the generation of test patterns can be provided with the layout ofthe drive circuit or a test drive circuit 202, as described withreference to FIG. 2, is integrated into drive circuit 102 so that onemust think of it as a single drive circuit 102. It is preferred, interalia, for this embodiment if the drive circuit provides input terminalsfor generating a test pattern and if these input terminals are connectedwith test contact areas.

Analogous to FIG. 11 b, input terminals 110 and output terminals 112 ofdrive circuit 102 can be distinguished in FIG. 3.

A possible realization of a test pattern as it can be generated with thepresent invention is shown in FIG. 4.

FIG. 4 illustrates the individual pixels as boxes. The letters in theboxes symbolize a potential applied to the electrodes of the pixelsduring generation of a test pattern. For example, different allocationto the pixels can be realized for two voltages V1=−7V and V2=+6V. Whichone of pixels A to D corresponds to a certain potential is determinedwithin the setup for the test. For example, A=B=C=V1 and D=V2 can beselected. Thereby, it is achieved that every pixel adjacent to a pixel Dwith potential V2 are on potential V1. By other selection ofallocations, like e.g. A=C=V1 and B=D=V2, horizontal stripes can begenerated.

As is apparent from FIG. 4, periodicity in vertical, horizontal ordiagonal direction can be generated by such a test pattern. In contrastto the above examples, it is further possible to allow more than twodifferent potentials. Thus, each pixel can be surrounded symmetricallyin the horzontal, vertical or diagonal by arbitrary voltages. A furtherpotential can be generated on the electrode of the picture elementitself.

Due to such a choice of a test pattern, which should not be understoodas a limiting example, every degree of freedom sufficient for a testpattern can be exploited because of the periodic arrangement of thepotentials of the electrodes of the picture elements.

For the generation of even more complex test patterns a patternaccording to letters A to H can be generated. Thereby, starting out fromone picture element a different potential value can be assigned to everyneighboring pixel.

Nevertheless, the driving of such a periodic pattern is less complexthan the generation of an arbitrary picture. Therefore, it is possibleto reduce the number of test contact areas compared to the number ofoperational contact areas. This allows to enlarge the contact areas usedfor the testing method. According ot the present invention, this resultsin an improved testing method since contacting error can be reduced.Moreover, the mechanics for contacting the display to be tested can bedesigned for high speed. Due to this optimization, the testing methodcan be further accelerated. Thereby, the throughput of the pieces to beinspected is increased.

The above described embodiments of the present invention can beadvantageously applied in a testing method according to the invention asit is described in the following. To reduce production costs, it isnecessary for, e.g. a LCD display, to undergo error checking during themanufacturing process. During error checking, the electrodes of theindividual picture elements and/or the switching elements forcontrolling the picture elements are tested. For this purpose, a beam ofcharged particles (particle beam), like an electron beam or an ion beam,or a laser beam can be used. In the following, the term particle beamcomprises laser beams, where the particles are photons, as well as aparticle beams where the particles are ions, atoms electrons or otherparticles.

In the following, the testing method is described by example of anelectron beam without limiting the invention thereto. A possible testingmethod is to charge the electrodes of the picture elements on apotential via the lines. This potential or its variation in time can bemeasured with the particle beam. Thereby, defects like short-circuits ormissing contacts as well as parasitic elements and their size can bedetected.

In another method, the electrodes of the picture elements are charged bya particle beam and the resulting potentials are measured by a particlebeam. Therein, the driving of the lines detemines the initial andboundary conditions.

In a further method, the electrodes of the picture elements are chargedby a particle beam and the current induced in the lines thereby ismeasured. Depending on the functioning of the drive circuit, it may benecessary to design the drive circuit so that such a current measurementis enabled at externally accessible contacts of the drive circuit.

In most of these methods it is necessary to provide signals to the linesof the picture elements or to measure the the signals at the lines.Therefore, the pads of the display elements must be connected with anexternal control or external measuring instruments. This contacting canbe improved by the apparatus according to the present invention.

In the testing method, the display to be tested is introduced into achamber and placed under the electron beam. Fir using the electron beam,the chamber has to be evacuated down to a pressure of below 10⁻⁴ mbar.Furthermore, a contacting block is connected with the test contact areasaccording to the invention. Typically, the contacting block is amechanics for making electrical contact between a testing device and thecontact areas of the display. Then, signals are transmitted to thecontact areas. Depending on the signals, the electrodes or individualelectrodes of the picture elements are brought to defined potentials.Thus, a test pattern is generated. The control of the testing devicetests the potentials of individual electrodes in that the electron beamis, inter alia, deflected by deflectors. Since no sufficient deflectioncan be realized for large displays, one portion of the display is testedfirst and, subsequently, the display is shifted by a shifting unit. Itis important for reliable testing that the contacting of the pads iscontinously maintained or can be reestablished reliably and quickly.According to the present invention, this is enabled by the test contactareas. After the shifting, another portion is tested. The interplay ofshifting the display and testing of a portion can be continued until thewhole display is tested or all displays on the substrate have beentested.

Inter alia, the testing speed is important for the above describedtesting method to achieve high throuhgput. Furthermore, the measurementmust be very reliable because even 0.1 per mill of defective pictureelements preclude use of the display. When defects are detected at anearly stage of the production process, error correction can beaccomplished by, e.g., an ion beam or laser beam.

Since even small leakage currents may result in noticeable imagedestortion due to parasitic elements, it is further preferred to equipthe testing device with sensitive testing methods. Therefore,electromagnetic interfering fields possibly interfering with theelectron beam or the measurement of secondary electrons or backscatteredelectrons must be largely avoided.

For the above mentioned reasons, the apparatus according to the presentinvention are preferred for the above described testing method becausecontacting the display within the testing device is facilitated due tothe test contact areas. Therefore, it is possible to realize anefficient contacting. This contacting complies with the above mentionedboundary conditions.

Without referring to specific embodiments, the following preferredaspects of the invention can be utilized in general for preferredsolutions of the problem underlying the present invention. It ispreferred if the second arrangement of contact areas is connected withthe drive circuit via the first arrangement of contact areas. Therein,the contact areas for generating the test pattern can be connected witha plurality of contact areas for regular operation. Furthermore, thenumber of test contact areas can especially preferably be reduced inthat not all operational contact areas connected with the drive circuitare connected with a test contact area.

Furthermore, it may be advantageous if a second arrangement of contactareas is connected with the drive circuit via a test electronics.Therein, it is especially preferred if the test electronics comprises amemory from which the test pattern to be generated is read. This testpattern can be provided to the drive circuit.

Also, it may be preferable if the second arrangement of contact areas isdirectly connected with the drive circuit. Therein, it is especiallypreferable if the drive circuit is such that it comprises circuits forprocessing the signals from the test contact areas.

The above mentioned aspects serve to further facilitate the testingprocess in that a separation of contact areas for the testing processand for regular picture generation is accomplished. Furthermore, itpossible due to these preferred aspects to reduce the number of contactareas for testing and, thus, to provide the option of enlarged contactareas for the testing procedure.

According to a preferred aspect, the number of second pads of the secondarrangement of contact areas is maximum 90% of the number of first padsof the first arrangement of contact areas. Preferably, the number ofsecond pads is maximum 50%, more preferably 20%, the number of firstcontact areas. Thus, it is possible and especially advantageous toprovide the second pas of the second arrangement of contact areas with adimension of at least 100 μm, preferably a dimension of 0.5 mm, andespecially preferred a dimension of 2 mm.

If the test drive circuit according to a preferred embodiment of thepresent invention includes a memory, it may be advantageous that thenumber of second pads of the second arrangement of contact areas usedfor signal transmission is one.

Without referring to specific embodiments, the following preferredaspects of the present invention can be applied, in general, for thetesting of an optoelectronic device according ot the present invention.

When testing an optoelectronic device according ot the presentinvention, it is preferred that the input signals generate a periodictest pattern. Therein, test patterns which are periodic in a vertical,horizontal or diagonal direction are especially preferred.

Moreover, the present invention has advantages when, during testing, avacuum is used in the vicinity of the optoelectronic device to be testedor when the testing method comprises the following steps: testing thepicture elements in a portion of the matrix of picture elements or allpicture elements of a smaller matrix; shifting the optoelectronicdevice, and testing of picture elements in a further portion of thematrix of picture elements or a further small matrix.

1-29. (canceled)
 30. A drive electronics for driving an optoelectronicdevice with a matrix of picture elements, having a drive circuit (102x), wherein the drive circuit has input terminals (110) and outputterminals (112); a first arrangement of contact areas (104) connectedwith the input terminals of the drive circuit (102 x); and a secondarrangement of contact areas (105) connected with the input terminals ofthe drive circuit (102 x), wherein the contact areas (105) of the secondarrangement of contact areas are larger than the contact areas (104) ofthe first arrangement of contact areas.
 31. The drive electronicsaccording to claim 1, wherein: the number of input terminals of thedrive circuit (102 x) by which the drive circuit is connected with thesecond arrangement of contact areas (105) is at most 5% of the number ofoutput terminals of the drive circuit by which the drive circuit isconnected with the control lines (103 x) of the matrix of pictureelements.
 32. The drive electronics according to claim 1, wherein: thefirst arrangement of contact areas (104) serves for picture generationduring normal operation; and the second arrangement of contact areas(105) serves for pattern generation during test mode.
 33. The driveelectronics according to claim 1, wherein: the second arrangement ofcontact areas (105) is connected with the drive circuit (102 x) via thefirst arrangement of contact areas (104).
 34. The drive electronicsaccording to claim 4, wherein: the second arrangement of contact areas(105) is connected with the drive circuit (102 x) via the firstarrangement of contact areas (104) by means of switching elements orcomponents.
 35. The drive electronics according to claim 4, wherein: thesecond arrangement of contact areas (105) is directly connected with thedrive circuit (102 x) via the first arrangement of contact areas (104).36. The drive electronics according to any of claim 1, wherein: thesecond arrangement of contact areas (105) is connected with the drivecircuit (102 x) via a test electronics (202 x).
 37. The driveelectronics according to any of claim 1, wherein: the second arrangementof contact areas (105) is directly connected with the drive circuit. 38.The drive electronics according to claim 8, wherein: test circuits areintegrated into the drive circuit.
 39. The drive electronics accordingto claim 1, wherein the number of second pads (105 b) of the secondarrangement of contact areas (105) is at most 90% of the number of firstpads (104 b) of the first arrangement of contact areas (104), preferablyat most 50%, more preferably at most 20%.
 40. The drive electronicsaccording to claim 1, wherein the second pads (105 b) of the secondarrangement of contact areas are larger than the first pads (104 b) ofthe first arrangement of contact areas.
 41. The drive electronicsaccording to claim 1, wherein the second pads (105 b) of the secondarrangement of contact areas have a dimension of at least 100 μm,preferably a dimension of 0.5 mm, and more preferably a dimension of 2mm.
 42. An arrangement of test contact areas for providing signals forgenerating a test pattern to an optoelectronic device comprising amatrix of picture elements, having: at least one pad (105 b); at leastone connection (105 a) of the at least on pad with a drive circuit (102x), which is provided with signals via an arrangement of operationalcontact areas (104) during normal operation; wherein the contact areas(105) of the second arrangement of contact areas are larger than thecontact areas (104) of the first arrangement of contact areas.
 43. Thearrangement according to claim 13, wherein: the drive circuit has inputterminals (110) and output terminals (112), and wherein the at least oneconnection (105 a) is connected with at least one of the input terminals(110).
 44. The arrangement according to claim 13, wherein: the at leastone pad of the arrangement of contact areas has a dimension of at least100 μm, preferably a dimension of 0.5 mm, and more preferably adimension of 2 mm.
 45. The arrangement according to claim 13, wherein:the number of pads (105 b) of the arrangement of test contact areas(105) is at most 90% of the number of pads (104 b) of the arrangement ofoperational contact areas (104), preferably at most 50%, and morepreferably at most 20%.
 46. The arrangement according to claim 13,wherein: the arrangement of test contact areas (105) is connected withthe drive circuit (102 x) via the arrangement of operational contactareas (104).
 47. The arrangement according to claim 13, wherein: thearrangement of test contact areas is connected with the drive circuit(102 x) via a test electronics (202 x).
 48. The arrangement according toclaim 13, wherein: the arrangement of test contact areas is directlyconnected with the drive circuit (102 x).
 49. An optoelectronic devicehaving a matrix of picture elements (101); a drive electronics accordingto any of claim
 1. 50. A method for testing an optoelectronic device,comprising the steps of: a) contact is made between an external controland an arrangement of test contact areas which are larger thanoperational contact areas; b) an input terminal of a drive circuit isprovided with input signals via the arrangement of test contact areas togenerate a test pattern on a matrix of picture elements; and c) thepicture elements of the matrix of picture elements are tested.
 51. Thetesting method according to claim 21, wherein the input signals generatea periodic test pattern.
 52. The testing method according to claim 21,wherein the input signals generate a vertically, horizontally ordiagonally periodic test pattern.
 53. The testing method according toclaim 21, wherein: the picture elements are tested with a beam ofcharged particles or laser radiation.
 54. The testing method accordingto claim 21, comprising the further step of: a vacuum is generated inthe vicinity of the optoelectronic device to be tested.
 55. The testingmethod according to claim 21, wherein step c) comprises the followingsteps: c1) the picture elements in a portion of the matrix of pictureelements are tested; c2) the optoelectronic device is shifted; and c3)the picture elements in a further portion of the matrix of pictureelements are tested.
 56. A method for manufacturing a drive electronicsof an optoelectronic device having a matrix of picture elements,comprising the steps a) a drive circuit is provided; b) control lines ofthe matrix of picture elements are connected with output terminals ofthe drive circuit; c) a first arrangement of contact areas is provided;d) the first arrangement of contact areas is connected with inputterminals of the drive circuit; e) a second arrangement of contact areasis provided, said contact areas being larger than the contact areas ofsaid first arrangement of contact areas; and f) the second arrangementof contact areas is connected with input terminals of the drive circuit.57. An optoelectronic device, which has been tested by a testing methodaccording to claim 21 or by an apparatus according to claim 1.